Toy helicopter



Jan. 9, 1951 P. E. BISCH ETAL 2,537,393

TOY HELICOPTER Filed July 27, 1946 I 4 2 Sheets-Sheet 1 P. E. BISCH ETAL TOY HELICOPTER Jan. 9, 1951 2 Sheets-Sheet 2 Filed July 27, 1946 Z l 4 z |NVENTOR5 PAUL BIS -H 13mm, T Dosem a v A-TTPRNEV Patented Jan. 9, 1951 UNITED STATES.- rATENr v TOY iz jms rauimnism mamvmmmnbms;

Los Angeles; Calif;

I r Application July 27, 1946, Serial no; comm.

This invention relates to toys and has as its general object to provide a toy helicopter that con be flown.

Helicopter-like toys including" an air screw adaptedto be set into" spinning movement-v by of launching deviceincluding? a draw string, on: old and well known, and it has alsobeen proposed to provide a: flying helicopter toy embodying a fuselage and a: sustaining rotor. However; the latter devices have not been definitely successful; The primary object of our inventionis, there fore, to provide a: toy helicopter including a fuse loge and sustaining rotor adapted. for successful flight, and landing.

Specific objects of the invention are: to pro vfdea. flying toy helicopter of relatively simple and inexpensive, yet sturdy and durable construction; to provide a toy helicopter embocying'. 2; rotor adapted for free spinning" movement relotive to the fuselage during flight; to providea toy helloopter embodying a rotor Proving a un-i'=- versed-1y pivotal-l connection with its fuslag'e; suck-r that the fuselage my swing during flight out disturbing the axis or rotation of the? rotor: to provide a toy helicopter the rotor is permitted to gain: lifting momentum heforev comm (cros -as) I take-off and maximum ap ying lift; to the fuselogcr order to overcoming the inertia: of the fiusaloge: the tasksofi to provide a, toy helicopter embodying? a novel simple; launching device including a: spindle adopted to vpass substantially through the fuse logo and; engage. a; rotor spinner when spirming power is applied. to; the; rotor, and to behindasthe fuselage away from the launch-- ing: device; to provide a toy helicopter embodying landing gear adapted to land. the toy an. up-

right; position, so as prevail; damage thereto during: landing; to provide toy helicopter which the center of and the: elastic: center of the fuselage (with reference to the landing wheelsl are both localized at the axis of rotation ofthe rotor, whereby to assure proper balancingofi the fuselage during: flight andproper' balancing of the entire;- toy during landing; to provide a toy helicopter embodying: simple yet efloctiv means for restraining the fuselage from rotationabout' the rotor axis both during launching? and during flight; to provide a. helicopter embodying: a mtor having bladesadapted; to automatically change pitch. flight so as. to achieve a combination of lifting power during distance of travel in the complete flight; and to provide a helicopter hav inga rotor embodying" an: autom'ttic dynamic balancing mechanism.

other objects will. become apparent in the ensuing specifications and appended drawingsirr which: 5

Fig; l is a side elevation of toy helicopter embodying my" Fig. 2'- is a lan view" of the same;

Fig. 3,is a sectional view through a rotor blade taken on the? line 3 -3 of 2;

Fig-t. 4 is a sectional view through a rotor blade taken on the-lime #4 of" Fig. 2-;

- Fig. 5 shows a tetiPsecfiom taken on the; line 5-5 of Fig. 1;

Fig. 6' is afdia mm rotor: adjustment:

Big. T is a; vertical sectional view taken on the line 1-1 of Fig. I; with the rotor bladesl'lowzr extending transversely with: reference fuselage;

Fig; 8- is a detail, inverted plan central portion of the rotor; Fig.- 9 1's 2; view the upper and of the pylon I r 1 Fig: l o--is a detarl sectional View taken on line [IL-l d ofFlg. 2; and

illustrating automatic view of the;

Fig. 11 is? side of pyl'm l v V 1 As an example one which our tion may. ho'embouied; wo have shown in fih' drawingsio; toy helicopter embodyfiag generally a combined 'fiusel'szgo landing" gear unit 1%,}?

. pylon. assembly B a; rotor" and a launching unit D: The pylon: ass mbly B'is adapted to receive" spinning movement transmittedth-ere't'o from the. launching: uni-tn; and in tumljto transmit this: spinning movement to the rotor 6' which,

\ at thecessation. of the? applied spinnmg' power,

isadapted: tofiree driving; of the pylon assembly B; to riseuporr the.

sh-artfu to engage this head ll and to thereupon; lift the fusologeand unit A. clear oi the launohing unit I fuselage-anal loading: gear uniiiA and rotor C are: constructed of at having a: relative ly high strength-weight ratio I find that 5; molded plastic: n'interiitl;r such: as celluloso ascctzte; is well suited for? the fuselage The fuselage is hollow and 'wtremely thin-walled? for example; the wa l-l liltfci me ss:trials; be as as is"? fora; fuselage measuring" approximately la /i 5 fuselagoma their an: integral molded he: symmetrical landing struction: or

3 ing the forward part thereof, an intermediate slender body portion-I3, and a tail portion IA. The fuselage is preferably constructed from a transparent material .the majority of which is provided with an opaque coating which is omitted from the area designated IS on the upper side' of the nose portion of the cabin l2. This cleararea I represents a window or windshield in :and terminate in weights 26.

the cabin, the opaque area representing the non- Windowed wall portions of the fuselage.

The landing gear includes struts l8, wheel fairings l1, and projections l8 representing wheels. The landing gear also includes a wheel 19 in a wheel fairing 2D in the tail [4. The wheels-i3 and 19 may be real wheels, mounted on an axle for rotation, or may be merely integral projections simulating a wheel, ormay be universally pivoted supporting elements such as a socketed ball, or a caster. The rear wheel i9 is preferably of anon-skid characteristic (e. g. of soft rubber) to prevent lateral skidding while the front wheels are hard and smooth to d a- The tail l4 functions to restrain rotation of the fuselage during flight of the craft. To this end, the rear end of the tail I4 is pitched downwardly and laterallylas shown in Fig. 5) in the facilitate lateral skiddirection of rotation of the rotor C. v For example,

where the rotonspins clockwise, as viewed from above, which is the case with the rotor shown in the drawings (as indicated byarrow 2| in Fig. 2) the tail l4 ispitched downwardly and clockwise as viewed from above.-; As-the result of this pitch in the tail Hi, the tail will develop a counterthrust (indicated-bythe arrow-22) in the downwash of the rotorC,- which counter-thrust is sufflcient. to oounteractthetendencyof the lightweight fuselag'e" to rotate with the rotor-C in response-t0 theslight amount' of frictional; torque that is transmitted through the bearings con-' nes e e o eih fv lae The landing wheels [8 are fairly widely spread apart and cooperate with -the tail projection [9 to provide a three-point landing gearso related to the rotor axis as to place the center of elasticity ofthe fuselageand landing gear assembly at a point on the rot r axis. Consequently, when the ,toy makes a landing, its; center of gravity (,which.--is ,also located on therotor axis so that the fuselage may be suspended in a balanced, horizontal condition during flight) will be sub-.. stantiallycentered between the three landing wheels 18 and 19 so as to minimize any tendency Qfthe craft-to bounce forwardly or rearwardly or to either side. is quite-important, since it provides for maintaining the toy in an upright position during and after landing.-and thereby avoids damage which would'be likely to occur, especially to the rotor, as the result of overturn- -T'he rotor C embodies a pair of blades 23 each having at its-tip a streamlined weight 24.7 The weights 24 have their longitudinal axes 24 dis p osed at an angle of incidence with reference to theplaneof rotor rotation, indicated at 21 in Fig. 3, such that-the weights will have a zero angle, of attack relative, to the: air through which the rotor is moving, while the blades 23 will have a positive angle of attack (indicated between the lines 24' and 23') The blades 23 have an approximately airfoil cross-section and an angle of attack gradually increasing to a maximum and then gradually diminishing from the rotor axis to the blade tips. A stable (non-tilting) plane of rotation of the rotor 1C is maintained by dynamic balancers comprised in arms 25 which project from the trailing edges of the blades 23, near the rotor axis, The weights 25 develop centrifugal forces tending to maintain the rotor in a non-tilting plane of rotation (indicatedby the broken line 21 in Fig. 4)

The blade tip weights 24 have a dual function. They serve to store energy during launching, and to deliver up this energy to the rotor for sustained flight. They also serve to provide an automatic ad ustment of the angle of attack of the blades in such a manner as to give a mimmumangle of attack at maximum speeds (at starting) and a maximum angle of attack at minimum speeds (at end of flight) The action of the weights 24 in producing automatic adjustment is shown schematically in Fig. 6. The leading edge of the wing is indicated by the line 55. The maximum ang e of attack is located adjacent the axis of a stabilizer arm 25 (indicated at the point 56). The leading edge 55 tapers toward the plane of rotation of the trailing edge (indicated at 5'!) both toward the blade tip and the rotor axis (indicated at 58). Consequently, the blade is arched from rotor axis to tip, and the centrifugal pull of the weight 2d (indicated at 59) will tend to reduce the arch and therefore to reduce the angle of attack. Consequently, at launching, the rotor biades will .have a minimum angle of attack, with minimum drag and lift- (resulting in maximum conservation of rotational speed and, therefore, of energy). As the rotor gradually loses speed during flight, the inherent resiliency of the blades W111 gradually increase the angle of attack, thus increasing the lift so asto compensatefor loss in -lift tending to-res ult from decreasingroto-rspeed; Thus, at some sacrifice of hcightrof flight, rotor speed and lift are maintained so as to min mize the fall of, the toy to the earth in the landing tage.

jThedynamic stabilizers 25,26 have, in addition totheir function of maintaining the rotor.

in a plane of rotation that is relatively non-tilting, another function, namely to assist in reducing the angle of attack of the rotor blades at high speeds. To this end, the arms 25 are'dise posed at an acute angle relative to the plane of rotation (indicated at 2-1 in Fig. 4) so as to twist the blades 23 toward a lesser angle of attack as, the weights 26 tend to move. into the plane 21 under; the effect of centrifugal force." The resil-'. iency of the reduced neck portionssfl of the blades.

23 yieldingly opposes this twisting moment, and urges the blades toward maximum pitch as rotational speed lessens. It is contemplated that this characteristic, in amplified form, may be utilize'din full size heli-. copters, With'a torsional spring connection between blade and hub taking the place of the yieldweights 26 utilized control.

Referring now to Figs. 5 to 8 inclusive, the fuselage isformed with an open-ended pylon neck as the sole means for pitch 3 l1in which is fi xed abearing bushing 3|. Jour,

flared. asiat 35 tcfacilitatemsertiortof thespindie 35... The upper end thespindle as has clntchnotch: 33. adapted: to receive a;.pirn.3'e which is'mounted in the spinner 32 and extends trans;- versely acrossrtheso'cliet 34. The spinner 32 has a 3% which. istbored. to receive a pylon shaft 39 extending upwardly from the center of the spinner. The lower end: of the shaft 39 is provided with a head 40 to engage the head 33in orderthat' the helicopter mayhesuspended from the shaft. To the upper end of the shaft 33ljis attached aretaining member: 4|: which receives support from the rotor C. For. the sake of. simplicity" and cheapness, I prefer to employgffor the: retaining member 61",. 'a nipple ofifresihent material such as" soft rubber; or its eqinvalen t, expanded over a roughened surface 421 at the end of the shaft 39 and secured by. corrtraotile engagement with the surface 42; The surface42*may-belznurledor indented or threaded or" otherwise roughened. The rotorC is provided, at its center; with an opening 43qthrough. which theshaft ea extends; with substantial clearance. The underside of the rotor is formed with a generally conical. recess 44. (Fig. 10) which is adapted'to receive the generally conical. upper;

surface fi of the head 38 (Field). and to provide" rotor C tends to rotate ahead of the spinner 32;,

disengagement of the rotor from the spinner will be quickly effected. The rotor, thus disengaged from the spinner, will spin freely on the shaft 39 and thereafter rise by its air screw action.

The pylon spinner 32 has a pilot 49 that'is receivable in the opening 43 in the rotor, for centering the rotor on the pylon. An importantfeature of the invention is the provision for universal freedom of movement between the rotor C and the shaft 39. This avoids interference with the gyroscopic orbit of the rotor by the fuselage and pylon, and thus provides stability in flight. Freedom of movement is provided for by the loose fit of the shaft 39 in the hole 43. Extra large diameter of the hole 43 also permits ample manufacturing tolerances for desired cheapness.

The launching unit D includes the spindle 35, a pulley 5| secured to its lower end, a combined handle and bearing sleeve 52 in which the spindle 35 is journalled, and a thrust ring 53' attached to the spindle 35 and engaging the upper end of the handle 52.

A pair of stay pins 54 are driven into the upper end of the handle 52 to form a yoke adapted to embrace the sides of the fuselage to hold the 6; fuseiage: andllanding gear unit: againstvrotatiois operation.

In the operation of myimprovedtoyhelicopten, the spindle 35 is insertedv through. art opening 552 in the bottom. of" the. fuselage and; is passed upwardly through. the. center at the fuselage. and into-the-socket 34 into engagement with the 31.. A. pulf oordifiil having a. handle it at onelendr, is: wound about the pulley 51E, thehandless 5E and 552 are: graspediizn thehands and. the; cord;

5B1 is ipu'llerh with: a; steady;. accelerating: pull; to: spinthe. spindle; 35 and. witheit: the spinner 32; roton 6;. During: the: pull,. the spindleith wilt freely rotate: in. the bearing; sleeve 52.: while is: easily absorbed. by the long bearing;

surface 'Iheaopening55 and bushing tit provide; spaced; bearings for the. spindle; 35,. thefnselage: in anuprightposition while the; spine die rotates therein. At. the. end of; the pull, the rotor 0,, the; spirmer" a2; and. the".- spindle 315 will. be: spinning; in. unison; butfi'the slight frictionah resistance: existing, within-i thewbearings; 32; 52. will; cause: the spindle. 35 and: spinner 325 to tend. to lag behind the rotor, resulting: in the above described. disengagement of, the: rotor from the spinners As. soon as the. rotor has become thus disengaged, it will. rise up the; shaft 39 into enegagement. with: the retain-mg member 4t and the momentum that ithas thus. attained will beutie lized. overcoming the inertia. of the fuselage:-

landing, gear. unit. A, Thus the. unit. A: will. be lifted; from...the.spindle- 3:5, thepin. 3'1 automatie cally. disengaging from-the. notch The. hell Copter. will. then be. in flight the launching unit, D remaining in. the. hands. of, the. operator.-

fluringf flight the down-wash. of. air acting against. the pitched portion. of the tail. it. will; produce the counter, torque 22. in the fuselagesutfihientl'yto counteract any torque transmitted to the fuselage. from the. rotor. through the shaft ti], and thus the fuselage will maintain a substantially non-rotating position while the rotor C continues to rotate under the energy stored in the blades 23 and weight 24. However, friction between the rotor and the shaft 39 and washer. 4|, is negligible. Thus the toy closely simulates the action of a real helicopter, the effect being quite impressive.

At launching, the speed of the rotor C will be at a maximum and the above referred to action of the weights 24 will cause the blades 23 to as.- sume a minimum angle of attack. As the rotor gradually loses momentum and speed, the inherent resiliency of the blades will cause them to return toward a normal unstressed angle of attack, thus maintaining lift. The reduction in angle of attack in the initial stage of flight provides for lower starting speed and less climbing. The maintenance of lift in the later stages of flight provides for prolonged sustentation during return of the toy to the earth, thus avoiding stalling, while the toy is still at a relatively high elevation. It is aimed to prolong the lift so that stalling will not occur until the toy has virtually reached a landing position, thus providing for a landing of maximum smoothness and safety. In landing, the toy will maintain an upright trim due to the centering of the center of gravity of the fuselage with reference to the axis of the pylon assembly B. When the craft alights, the shock will be centered between the landing points l8 and I9 due to the location of the center of elasticity of the fuselage, with reference to the landing points, and to the pylon axis, 1. e. at

the same point as the center of gravity. As a re 7. sult the rebound force will be applied at the center of gravity and there will be a minimum tendency for the craft to overturn.

We claim as our invention:

1. In a toy helicopter, a fuselage, a pylon assembly rising from the upper side of said fuselage, said pylon assembly including a spinner journalled with reference to the fuselage and having at its upper end a clutch device, and a shaft rising therefrom, a rotor freely journaled on said shaft and having in its under side clutch means for coaction with said clutch device for receiving spinnin movement from said spinner, said rotor being adapted, upon cessation of launching movement, to disengage from said clutch device and rise upon said shaft, said shaft having at its upper end abutment means adapted to be engaged by said rotor for transmitting lifting support from the rotor to the fuselage, and launching means adapted to be passed upwardly through the fuselage into driving connection with said spinner, said launching means and spinner including disengageabie coupling means for effecting said' driving connection.

2. In a toy helicopter, a fuselage, a pylon assembly including a spinner journalled substan-- co-action with said clutch device for receiving rotation from said spinner, said rotor being adapted, upon cessation of launching movement, to disengage from said clutch device and rise upon said shaft, said shaft having at its upper end abutment means adapted to be engaged by said rotor for transmitting lifting support from the rotor to the fuselage. t

3. In a toy helicopter, a fuselagea pylon assembly including a spinner journalled substan tially vertically with reference to the fuselagev and having at its upper end a clutch device,-a. shaft rising from said spinner, a rotor freely:

journalled on said shaft and longitudinally slidable thereon, said rotor having clutch means for co-action with said clutch device for receiving. rotation from said spinner, said rotor being: adapted, upon cessation of launching movement;

to disengage from said clutch device and rise upon said shaft, said shaft having at its upperend abutment means adapted to be engaged by;

saidrotor for transmitting lifting support from the rotor to the fuselage, and launching meansengageable with and adapted to transmit rotation,

REFERENCES CITED The following references are of record in th file of this patent: I

UNITED STATES PATENTS Number Name Date 1,718,577 Pitcairn June 25, 1929 1,917,965 Gerhardt July 11, 1933 1,967,461 Ballew July 24, 1934 2,012,600 Fischer Aug. 27, 1935 2,035,531 Butcher Mar. 31, 1936" 2,070,657 Hafner Feb. 16, 1937 2,106,557 Putnam Jan. 25, 1938 2,369,652 Avery Feb. 20, 1945 1 2,400,704 Moore May 21, 1946 r 2,489,343 Wasserman Nov. 29, 1949 FOREIGN PATENTS Number Country Date 236,749 Germany July 11, 1911 672,424

Germany Mar. 2, 1939- 

